Detection and quantification of 5 enolpyruvylshikimate-3-phosphate synthase (cp4 epsps) upon Brassica napus × Brassica juncea outcrossing using real-time PCR

Oilseed rape (Brassica napus L.) is an important agronomic crop used for oil, food and animal feed. Glyphosate resistant B. napus is tolerant to the herbicide glyphosate and has been widely adopted due to higher economic returns. However, a concern for growing transgenic B. napus is the potential escape of cp4 epsps transgene via cross fertilization with wild and/or weedy species including Brassica juncea, especially in China, where B. juncea is prevalent. We assessed transgene inheritance and quantification upon wild B. juncea × transgenic B. napus outcrossing from three backcross (BC) generations and their progenies using real-time PCR. Under in vitro conditions, a stable inheritance and similar cp4 epsps copy number between different generations (BC2, BC3 and BC4) and their progenies were observed. A marginally higher copy number was observed when B. juncea was used as the paternal as compared to when it was used as maternal parent. This study demonstrates stable inheritance of the glyphosate resistance trait and the production of fit out crossed offspring in cases of wild type B. juncea × transgenic B. napus. © 2009 Springer-Verlag.